Anthropic releases Claude Opus 5, positioning a cheaper model near Fable 5 performance

Anthropic has released Opus 5, a new Claude model that it says comes close to its higher-end Fable 5 model at half the price while improving on Opus 4.8 in knowledge work, coding, and scientific research tasks. "At the same time, Anthropic says it has managed to make the model more resistant to being tricked," notes Engadget. Additionally, the company says Opus 5 "exhibits the lowest rates of deceptive behavior." From the report: One important distinction between Opus 5 and Mythos, which is currently only available to a limited number of vetted organizations through Anthropic's Project Glasswing initiative, is that the company has specifically avoided training the new model on cyber-related tasks. Due to more its powerful capabilities, Opus 5 is broadly better at those tasks than its predecessor, making it more useful for finding cybersecurity vulnerabilities, but the company says Opus 5 is "substantially behind" its flagship model at exploiting those vulnerabilities. [...] Anthropic says "Claude Opus 5's safeguards are designed to allow beneficial uses of the model in both cybersecurity and biology." The company has strengthened some of the model's cyber-related guardrails, but notes it did so along a "narrow range" of specific tasks. "Based on our testing, we expect the classifiers to intervene around 85 percent less often than they do for Fable 5," Anthropic said. With Opus 5, Anthropic also isn't including it in its recently announced 30-day data retention policy, which the company introduced alongside Fable and Mythos 5. As for pricing. Anthropic says API costs for Opus 5 will remain at $5 per one million input tokens and $25 per one million output tokens. Anthropic has also added an "effort" menu for Opus that users can tweak to tell the model whether they want it to be more thorough or fast and efficient to conserve tokens. Read more of this story at Slashdot.

Anthropic on Friday released Claude Opus 5, a new artificial intelligence model the company says approaches the performance of its most powerful system at half the price. The San Francisco-based startup, a chief rival to OpenAI, said the model tops industry benchmarks for coding and knowledge work while consuming fewer computing resources than earlier versions. The claim addressed the rising concerns of business customers who have baulked at the expense of running advanced AI systems. Claude competes with OpenAI’s ChatGPT and Google’s Gemini, and customers pay based on the amount of work performed, measured in units called tokens. Opus 5 costs $5 per million input tokens and $25 per million output tokens, half the price of Fable 5, Anthropic’s most expensive publicly available offering. The company said the new model performs close to Fable 5 across many tasks despite the lower cost. Cost has become a major issue after Anthropic and its archrival OpenAI, the maker of ChatGPT, both filed for stock market listings in June. Wall Street is scrutinising their business performance more closely than ever ahead of their market debuts. On cybersecurity, Anthropic said it deliberately avoided training Opus 5 on cyber tasks, and that the model remains behind Mythos 5 — its most capable and most tightly restricted system, available only to select partners — on both offensive cyber work and biological research capabilities that could be misused. Mythos is Anthropic’s most advanced series of AI models, and its strength at finding weaknesses in computer systems — and at turning those weaknesses into working attacks — has caused controversy and pushed the company to build tight guardrails around them. The company said Opus 5 finds software flaws about as well as Mythos 5 but lags far behind in turning those flaws into something that could be weaponised into an attack. Citing the reduced risk, Anthropic said its automated safety filters will intervene roughly 85 per cent less often on Opus 5 than on Fable 5, the Mythos-class model it released last month. Fable 5 and Mythos 5 were briefly pulled from public access in June after the US Commerce Department imposed export controls, which were lifted at the end of that month.

Anthropic today introduced Claude Opus 5, an upgrade to Opus 4.8. Anthropic says Opus 5 was built for daily use, and it offers near Fable 5 performance at half the price. Fable 5 is Anthropic's most capable publicly available model. Opus 5 scores higher than Opus 4.8 on multiple benchmarked tasks, including agentic coding, novel problem solving, knowledge work, computer use, and multidisciplinary reasoning. It is a "meaningful improvement" over Opus 4.8 for scientific research, and it can produce better visual outputs. Anthropic says the new model "provides greatly improved performance for the same cost" as Opus 4.8. Opus 5 is better at verifying its work and iterating until it completes a task. It is close to Mythos 5 at finding cybersecurity vulnerabilities, but it was not trained on cyber tasks and it remains "substantially behind" Mythos 5 on exploitation. Mythos 5 is Fable 5 with some safeguards removed. It is limited to a small number of organizations, mostly cyberdefenders and infrastructure providers because of its capability at finding and exploiting vulnerabilities. Opus 5 is available on all platforms. It is the new default model on Claude Max and the strongest model available on Claude Pro. It is priced at $5 per million input tokens and $25 per million output tokens, which is the same as Opus 4.8. Fast mode is also available, running at 2.5x the default speed for twice the base price.Tag: AnthropicThis article, "Anthropic's New Claude Opus 5 Nearly Matches Flagship Fable 5 at Half the Cost" first appeared on MacRumors.comDiscuss this article in our forums

Anthropic released Claude Opus 5 on Friday, a model the company says delivers nearly all the intelligence of its top-of-the-line Claude Fable 5 at half the cost — a launch that signals how the AI race is shifting from raw capability to the economics of daily use.The model, available immediately on all of Anthropic's platforms, is priced at $5 per million input tokens and $25 per million output tokens, unchanged from its predecessor, Opus 4.8. It becomes the new default model on Claude Max, Anthropic's premium consumer tier, and the strongest model available on Claude Pro.The positioning is deliberate. Anthropic is not claiming Opus 5 is its smartest model — that distinction still belongs to Fable 5, and rival systems retain an edge in certain domains. Instead, the company is making a subtler argument that may matter more to enterprise buyers: that the most economically important AI work happens in a middle band of difficulty, where near-frontier intelligence delivered efficiently and cheaply beats frontier intelligence delivered expensively."Opus 5 as your daily driver, the model you hand complex work to and review when it's done," an Anthropic spokesperson said in an interview with VentureBeat, describing how the company's lineup now stratifies. "Fable 5 for your most ambitious work, the days-long autonomous projects nothing could take on before... Sonnet 5 for work you run at scale, where speed and cost per call decide what ships. Haiku 4.5 for subagents and instant answers."How Claude Opus 5 benchmark results stack up against Fable 5 and rival AI modelsOn paper, the results are striking. Anthropic says Opus 5 sets new state-of-the-art marks on coding and knowledge-work evaluations including Frontier-Bench and GDPval-AA. On Frontier-Bench v0.1, an agentic terminal coding benchmark, Opus 5 scores 43.3 percent — more than double Opus 4.8's 18.7 percent and well ahead of Fable 5's 33.7 percent — at a lower cost per task, according to the company. On ARC-AGI 3, an evaluation of novel problem-solving, Anthropic reports Opus 5 scored three times as high as the next best model. On OSWorld 2.0, a computer-use benchmark, the company says the model surpasses Fable 5's best result at just over a third of the cost.The numbers come with honest caveats that are themselves notable in an industry prone to superlatives. Anthropic acknowledges Opus 5 remains behind Mythos 5, a competing model, on cybersecurity tasks and biology research, and an OpenAI-family model still leads on one agentic coding benchmark.The more revealing caveat came from Anthropic itself, when asked where Opus 5 still falls short of Fable 5. The spokesperson's answer amounted to a candid admission about what benchmarks do and don't capture."The evals where Opus 5 wins are bounded tasks with a specific outcome, which is where it's strongest. What those evals don't measure is duration," the spokesperson told VentureBeat. "One way to put it: Opus 5 is the best tool for the jobs benchmarks can see, and Fable 5 is what you reach for when the job outruns the benchmark."Fable 5, by contrast, "is for the longest, most autonomous jobs, where the model has to stay coherent across many connected steps over hours or days with dense source material," the spokesperson said, advising customers to "run both on a representative workload, one bounded task and one long-horizon job." That framing — bounded tasks versus long-horizon autonomy — may become the defining axis of model differentiation in 2026, as benchmarks saturate and the hardest remaining problems involve sustained, multi-day agentic work rather than discrete puzzles.Why token efficiency is becoming the real battleground for enterprise AI spendingThreaded through the launch is a theme Anthropic clearly wants buyers to absorb: Opus 5 doesn't just score well, it scores well per dollar. The model ships with an adjustable "effort" setting that lets customers trade intelligence for speed and token savings, and Anthropic's charts emphasize performance at a given cost rather than peak performance alone.Early customers echoed the point with unusual specificity. Harvey, the legal AI company, said Opus 5 achieved similar performance to Opus 4.8's maximum-reasoning mode "while generating 26% fewer tokens on average," according to Niko Grupen, its head of applied research. Richard Pham of Fundamental Research Lab said that on hard financial-modeling tasks, the model averaged nine percentage points higher accuracy "while using roughly one-third fewer turns and tool calls and 60% less time."Wade Foster, chief executive of Zapier, said Opus 5 topped his company's AutomationBench leaderboard "without spending more tokens than prior Claude models," running a full churn-prevention workflow from start to finish. "Previous models didn't pass; Opus 5 hit 100%," he said. Scott Wu, chief executive of Cognition, the company behind the Devin coding agent, said that on FrontierCode 1.1, "Claude Opus 5 approaches Fable-level performance at half the cost," with particular strength in debugging and root-cause analysis.The efficiency emphasis reflects commercial reality. Enterprise AI spending is no longer experimental, and inference costs — the price of actually running these models at scale — have become a board-level line item. Anthropic's business skews heavily toward API and enterprise usage; according to a February 2026 analysis by Contrary Research, Claude held roughly 40 percent of the enterprise large language model market by usage as of late 2025, and Claude Code alone had reached about $1 billion in annualized revenue. For a company whose customers pay by the token, a model that does more with fewer tokens is not a nice-to-have. It is the product.Self-verifying AI agents and what they mean for the hidden costs of automationBeyond the numbers, Anthropic is selling a behavioral story: that Opus 5 verifies its work and iterates until it succeeds. The company offered several examples from testing that read like small parables of machine stubbornness.In one Frontier-Bench task, the model was asked to reconstruct a machine part as a 3D CAD model from a drawing it was intentionally given no way to view. Rather than fail, Anthropic says, Opus 5 wrote its own computer vision pipeline to extract the geometry from raw pixels — and did so repeatedly, while no competing model solved the task in five attempts. In another case, given a real bug in a popular open-source package manager, the model found the root cause and fixed an edge case the community's own patch had missed; a competing model patched only the symptom and declared victory. An engineer at a trading firm, the company says, used Opus 5 to build a market data feed for a new exchange in a single session and, finding no live feed to validate against, watched the model build its own test harness to check its parsing code.Customers described similar behavior in the wild. Cristian Rivera, a staff software engineer at Stripe, said he gave the model "a chief-of-staff role over my dev environments" for a weekend: "it built its own monitor, drove each box, and pulled me in only for the judgment calls."This is the capability enterprises actually care about, and it is worth dwelling on why. The gap between a model that produces plausible output and one that verifies its output is the gap between a demo and a deployable system. Most of the hidden cost of enterprise AI today is human review — engineers checking the machine's work. A model that reliably checks its own work compresses that cost, which is precisely why customers keep citing fewer turns, fewer passes, and less time rather than higher raw scores.Inside Anthropic's safety strategy: capability gaps, classifiers, and model fallbacksThe launch also showcases Anthropic's increasingly intricate approach to safety — one that now involves deliberately not teaching its models certain skills. The company says its automated behavioral audit found Opus 5 to be its most aligned model to date, scoring 2.3 on overall misaligned behavior, lower than Opus 4.8, Sonnet 5, or Fable 5, with the lowest rates of deceptive behavior and the least susceptibility to being tricked into misuse.On the capability side, Anthropic says it intentionally avoided training Opus 5 on cyber tasks, as it did with Opus 4.8. The model improved on them anyway — a side effect of general capability gains — and now nearly matches Mythos 5 at finding software vulnerabilities. But it remains far behind at exploiting them: on Anthropic's OSS-Fuzz evaluation, Opus 5 identified vulnerabilities at a 79.4 percent rate, close to Mythos 5's 80 percent, but succeeded at developing exploits in only 4 challenges versus Mythos 5's 13. That asymmetry — strong at defense-relevant discovery, weak at offense-relevant exploitation — appears to be by design, and the safeguards follow the same logic. Anthropic expects Opus 5's cyber classifiers to intervene about 85 percent less often than Fable 5's.When a classifier does trigger, requests in Claude.ai, Claude Code, and Claude Cowork fall back to Opus 4.8 by default — raising an obvious question: if a request is too risky for one model, why is it acceptable for another? "The model it falls back to has lower capability levels making the risk of harmful use lower as well," the spokesperson said, adding that "there is a message that lets the user know when this occurs and is visible in the chat."The logic is defensible, but it reveals how AI safety actually works in 2026: risk is not a property of the question alone, but of the question multiplied by the capability of the system answering it. On biology, the calculus runs the other way. Opus 5 is now Anthropic's most capable generally available model for scientific research — scoring 10.2 percentage points higher than Opus 4.8 on the company's internal chemistry benchmark — though the spokesperson acknowledged that "Mythos 5 remains the stronger model for long-horizon, open-ended work like autonomous drug design campaigns."The business stakes behind the launch: a $380 billion valuation and massive compute betsThe launch lands at a moment of extraordinary commercial momentum — and extraordinary obligations — for Anthropic. Reuters reported in February that the company was valued at roughly $380 billion in its latest funding round, following a period in which, per Contrary Research's analysis, its annualized revenue climbed from about $1 billion at the end of 2024 to a projected $9 billion by the end of 2025, with internal targets reportedly reaching $20 to $26 billion for 2026. Those targets are underwritten by enormous infrastructure commitments, including a reported $30 billion Azure compute deal alongside arrangements with Google Cloud and Nvidia — spending that only pencils out if enterprises keep expanding usage.That is the context in which Opus 5's pricing strategy makes sense. Holding the price at Opus 4.8 levels while roughly doubling performance on key agentic benchmarks is effectively a steep price cut per unit of capability, designed to widen the funnel of workloads that are economical to automate. Every task that was marginal at Opus 4.8's cost-per-success becomes viable at Opus 5's — and every viable task is recurring token revenue.The regulatory backdrop has grown more complex as well. A U.S. judge gave final approval this week to Anthropic's $1.5 billion copyright settlement with book authors, Reuters reported, closing a chapter of litigation over the company's early training data. And in June, Reuters, citing Axios, reported that the U.S. government had moved to block foreign access to Anthropic's most advanced models — a reminder that frontier AI is now entangled with export policy in ways that shape which customers can buy what.Also shipping Friday: a Fast mode running at roughly 2.5 times default speed at twice the base price, automatic fallback routing on the API, and mid-conversation tool changes that no longer invalidate the prompt cache — a small feature that agent developers may appreciate more than any benchmark. Consistent with prior Opus models, Opus 5 carries no data retention requirements for general access, a point the spokesperson flagged unprompted for customers with "a hard zero data retention requirement." Developers can access the model as claude-opus-5 on the Claude API starting today.Two questions will determine whether the bet pays off: whether Opus 5's efficiency claims survive contact with production workloads at scale, and whether enterprises embrace a world where safety classifiers, not users, sometimes decide which model answers. But the deeper message of Friday's launch is that the AI industry's center of gravity has moved. For three years, the labs competed on what their best model could do on its best day. With Opus 5, Anthropic is competing on something less glamorous and far more lucrative: what a very good model can do every day, for half the price. In a market where the frontier keeps moving, Anthropic is wagering that the real fortune lies just behind it.

Today Anthropic released its new Opus 5 model, which the company claims delivers performance comparable to its more advanced Fable 5 model at half the price. Opus 5 is designed for both complex coding and general office work. Anthropic says the model can make its way through the steps of a complicated problem without much back-and-forth with the user. Plus, it can check its own work and recover from errors rather than getting stuck. It also shows improvements over its predecessor, Opus 4.8, in complex coding tasks. The company calls it its strongest model yet for general knowledge work. A broader range of professional tasks The release is part of Anthropic’s effort to expand Claude beyond chat and code generation, and into a broader range of professional tasks, including design, marketing, accounting, and the analysis of large document sets. What makes Opus 5 notable, however, is its proximity to Fable 5, the most advanced model Anthropic has made broadly available. Fable is significantly better than previous releases at writing software, working through long projects with limited supervision, and handling especially difficult assignments. The U.S. government even became alarmed at the model’s capacity to discover and exploit software vulnerabilities in cyberattacks. (Fable 5 is the public version of another Anthropic model, Mythos 5, which is even better at cyber defense—and offense—and available only to the government and select organizations working on cybersecurity and critical infrastructure.) Scientific research Opus 5 costs $5 per million input tokens and $25 per million output tokens. An API customer might use it for routine coding or general office tasks, then switch to the more powerful and more expensive Fable 5 model for the hardest work. Anthropic also says Opus 5 is its most capable generally available model for scientific research, citing performance gains on biology tasks compared with Opus 4.8. The company said this could benefit researchers integrating the model into engineering and analysis work. The model includes adjustable effort levels—low, medium, and high—so that users can make their own trade-offs between cost and capability. Anthropic says Opus 5 is its most cost-efficient model on the DeepSearchQA and Humanity’s Last Exam benchmarks for models that use tools. Anthropic is offering Opus 5 “fast mode” (available in the Claude chatbot and Claude Code), which offers 2.5 times faster output token generation at about twice the standard price of the model. The company is releasing the feature as a “research preview” to all API users, with the aim of collecting data on how and when people use it.  Opus 5 will be the default model for users with Claude Max subscriptions, Anthropic says, with standard token limits on all paid plans.